Dual purpose sheet handling apparatus

ABSTRACT

A pair of rollers defining a nip transporting sheets in a first direction for a first mode of operation. A clutch operated drive belt rotates the frame supporting the rolls about an axis through the nip to invert the sheets for a second mode of operation. At the same time a releasable latch serves to release and then stop the frame after rotation through an angle of about 180* for the second mode of operation.

United States Patent 1 Kubasta [4 1 Nov. 4, 1975 DUAL PURPOSE SHEET HANDLING APPARATUS [75] Inventor: Charles J. Kubasta, Plano, Tex.

[73] Assignee: Xerox Corporation, Stamford,

Conn.

[22] Filed: Dec. 7, 1973 [21] Appl. No.: 422,822

[52] US. Cl. 271/65; 198/239; 271/186 [51] Int. Cl. B6511 29/00; B65G 42/24 [58] Field of Search 198/239; 271/65, 186, 185

[56] References Cited UNITED STATES PATENTS 3/1957 Connell 198/239 3,610,397 10/1971 Bok 198/239 X 3,744,614 7/1973 Shooter et a1. 198/239 Primary ExaminerEvon C. Blunk Assistant ExaminerBruce H. Stoner, Jr.

[ ABSTRACT A pair of rollers defining a nip transporting sheets in a first direction for a first mode of operation. A clutch operated drive belt rotates the frame supporting the rolls about an axis through the nip to invert the sheets for a second mode of operation. At the same time a releasable latch serves to release and then stop the frame after rotation through an angle of about 180 for the second mode of operation.

4 Claims, 4 Drawing Figures Sheet1of3 3,917,256

U.S. Patent Nov. 4, 1975 FIG.

US. Patent N0v.4, 1975 Sheet2of3 3,917,256

Sheet 3 of 3 FIG. 4 v

US. Patent Nov. 4, 1975 DUAL PURPOSE SHEET HANDLING APPARATUS This invention relates to sheet handling apparatus and is especially for use with reproduction systems capable of producing simplex and duplex copies.

With advent of high sophisticated copier/duplicator systems there has been a growing concern for the rapid and reliable distribution and handling of the copy sheets in both simplex and duplex modes of operation. In the past sheet inverting devices principally used in handling of documents for recording on both sides as described, for example, in US. Pat. Nos. 3,408,140, 3,416,791, 3,561,865 and 3,227,444. Also it is known to turn cards and the like for copying as described, for example, in U.S. Pat. No. 2,901,246. While the existing devices are suitable for some applications they are not entirely satisfactory for high speed sophisticated reproduction machine capable of operating in simplex and duplex mode of operation.

The present invention is an improved sheet handling apparatus desirable for use with high speed copier/duplicators of all types including simplex and duplex systems. Generally speaking, this is accomplished by a sheet inverter including pinch rolls which when rotated on axis through the nip result in sheet inversion with trailing edge becoming leading edge. As a result sheet inversion is accomplished without a separate feed path or reversing the sheet drive.

It is-therefore a general object of the invention to improve the handling of sheets.

It is another object of this invention to enable inverting sheets without reversing the drive of the sheet transport.

It is still a further object of the invention to enhance the sorting of copy sheets in both simplex and duplex modes of operation.

It is still a further object of the invention to achieve sheet inversion in a simple and reliable manner.

The above and added advantages of the present invention will be more apparent after reading the following detailed description which refers to accompanying drawings in which:

FIG. 1 is a perspective view of a high speed copier/- duplicator system capable of duplex operation including an improved sheet handling apparatus according to the present invention;

FIG. 2 is a schematic view illustrating the xerographic components of the copier/duplicator system;

FIG. 3 is a side view of the sheet handling apparatus; and

FIG. 4 is a plan view of the sheet handling apparatus.

FIG. 1 shows a copier/duplicator system generally designated 2 including a copier machine 3, which is a high speed copier/duplicator capable of producing simplex or duplex copies at the option of a machine operator. The copier machine 3 has a platen 4 for receiving documents to be reproduced, and a control panel 5 which includes various control knobs, buttons and switches for selecting various modes of operation such as simplex and duplex copies and the number of copies to be reproduced. In accordance with the invention, the copier/duplicator system includes sheet handling apparatus 8 which directs the copies into a sorter generally designated 6.

As best shown in FIG. 2, the copier/duplicator system includes an automatic xerographic apparatus which includes a photosensitive plate including a photoconductive layer 10 that is placed over a conductive backing. The plate is formed in the shape of a drum 11 and the drum mounted upon a shaft 12 that is journaled for rotation in the machine frame. Basically, the xerographic drum is rotated in the direction indicated so as to pass sequentially through a series of xerographic processing stations. The photosensitive drum and the xerographic processing apparatus are driven at predetermined speed relative to each other from a drive system (not shown) and the operation thereof coordinated in order to produce proper cooperation of the various processing mechanisms.

The original, to be reproduced, is placed upon a transparent horizontally supported platen 4 and the original scanned by means ofa moving optical scanning system and to produce a flowing light image of the original. The scanning system includes an elongated horizontal extended aperture lamp l5 and a movable lens element 18. The lamp and lens element moves in coordination across the object supported upon the platen to focus successive incremental bans of illumination reflected from the object onto the moving drum surface at synchronous speeds therewith. The optical path is folded by means of a pair of image mirrors l9 and 20 interposed between the lens and drum surface, the drum is first uniformly charged by means of a corona generator 13 positioned in charging station A. Under the influence of the flowing light image, the uniformly charged photoconductive surface is selectively dissipated in the non-image areas to form what is commonly known as a latent electrostatic image.

The latent electrostatic image is carried on the drum surface from the exposure station into the developing station C. The developing station primarily is comprised of a developer housing 22 adapted to supported a supply of two-component developer material 21 therein. The developer material is transported by means of a bucket system 23 from the bottom of the developer housing to an elevated position where the material is delivered into the active development zone. The developer material is caused to flow downwardly in contact with the upwardly moving drum surface under closely controlled conditions wherein charged toner particles are attracted from the .developer mix into the image areas on the plate surface thus making the image visible.

The moving drum surface'next transports the developed xerographic image to a transfer station D. Cut sheets of final support material are also moved into the transfer station, the backside of the copy sheet is sprayed with an ion discharge from a transfer corotron 25 including on the sheet a charge having a polarity and magnitude sufficient to attract the toner material from the drum surface to the final support material. This induced charge also electrostatically tacks the final support material to the drum surface. In order to remove the copy sheet from the drum surface, a stripper finger 28 is positioned downstream from the transfer corotron. The finger is arranged to move between the drum surface and the copy sheet and lifts the sheet from the drum surface and the copy sheet is directed along a predetermined path of travel into contact with a stationary vacuum transport 29.

Although a preponderance of the toner material is transferred from the drum surface to the copy sheet during the transfer process, invariably some residual toner remains behind on the drum surface after transfer. The residual toner is transported on the drum surface into a cleaning station E where it is brought under the influence of cleaning corotron 30 adapted to neutralize the electrostatic charge tending to hold the residual toner to the drum surface. The neutralized toner is mechanically cleaned from the drum surface by means of a brush or the like and the toner collected within a housing 31. A conveyor moving in an endless loop through tubes 32 transport the collected residual toner back to the developer housing where it is deposited within the developer mix so that it can be once again reused in the xerographic developing process.

The copy sheet, which has been removed from the drum surface after the transfer operation, is moved along stationary transport 29 into fusing station F. The fuser 33 is basically made up of an upper fuser roll 34 and a lower fuser roll 35 mounted in operative relation to each other and arranged to coact so as to support a sheet of material in pressure driving contact therebetween. The lower roll is heated. As the heated roll is rotated in the direction indicated, the heated surface of the lower roll is pressed into intimate contact with the image face of the support sheet. Mechanical and heat energy transported from the roll surface to the support sheet to permanently bond the toner particles to the support material.

Upon leaving the fuser, the fixed copy sheet is passed through a curvalinear sheet guide system, generally referred to as 39, into cooperating advancing rolls 43 and 44. At this point, depending on the mode of operation selected, the copy sheet is either forwarded directly to the sorter or into upper supply tray 52 by means of a movable sheet guide 45 before entering the sheet handling apparatus 8. For simplex copying the copy sheet is advanced directly to the sheet handling apparaus 8 to invert the sheet before delivery to one of the trays of sorter 6 or the like. A typical sorter is described in copending application Ser. No. 319,957, filed Dec. 29, 1972 now US. Pat; No. 3,788,640 and commonly assigned herewith.

It is believed that the foregoing description is sufficient for purpose of the present application to show the general operation of a xerographic reproducing machine. For a more detailed explanation of the copier/- duplicator xerographic components reference is made to U.S. Pat. No. 3,645,615 entitled Copying Apparatus.

Referring now to FIGS. 3 and 4, the sheet handling apparatus 8 includes a frame 9 supporting rolls 101 and rolls 103 which receive copy sheets from the copier/duplicator and either inverts the copy sheets before ad vancing them to the tray assemblies or advances them directly to the tray asssemblies according to the mode of operation. Rolls 101 are driven by a belt 110 rotating continually in a counter-clockwise direction for transporting the copy sheets S towards the sorter 6. For simplex operation signals from a sheet sensor, as for example a lamp and photocell pair 111 trigger sheet handling apparatus 8 to enable the sheets S to be inverted prior to delivery to the sorter 6. Signals serve to energize a clutch 115 engaging a belt 120 which rotates the frame carrying rolls 101 and 103 at the same speed and direction at which the rolls are turning. At the same time signals to solenoid actuated latch 121 serves to release the frame enabling the rolls 101 and 103 to rotate on an axis. through the nip N. There is no apparent movement of the rolls. Latch 121 re-engages the frame and the clutch is de-energized after 180 of the frame carrying the rolls. It will be appreciated that during rotation the sheet S is not advanced but wrapped around the rolls. As a result the trail edge of the sheet S becomes the lead edge and the top becomes the bottom of the sheet which accomplishes sheet inversion. The sheet is advanced towards feed rolls and 132 which feed it towards sorter 6. On the second sheet a similar operation occurs with rotation of the frame for a second This operation continues with a full 360 rotation for each two sheets.

By the above described invention the copy sheets are inverted or delivered directly without inversion to a sorter from a copy processor depending on whether simplex or duplex operation is used. It will be appreci ated that the sheet handling apparatus accomplishes the transport of the sheetswithout requiring a separate path or a reversing drive for sheet inversion.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is:

1. In a reproducing system in which simplex and du-.

plex copies are made in a processor and then distributed, an improved sheet handling apparatus comprising:

a rotatable frame,

first and second roll means supported by said rotatable frame defining a nip for receiving copy sheets from a processor,

first drive means for continuously driving said first roll means on its axis, second drive means for rotating said frame carrying said first and second roll means about an axis through said nip at substantially the same speed and in the same direction as that of said first roll means, and control means to actuate said second drive means in response to signals to rotate said frame carrying said roll means about an angle of 180 about an axis trical signals actuate a solenoid operated latch released momentarily out of the path, of said frame. 

1. In a reproducing system in which simplex and duplex copies are made in a processor and then distributed, an improved sheet handling apparatus comprising: a rotatable frame, first and second roll means supported by said rotatable frame defining a nip for receiving copy sheets from a processor, first drive means for continuously driving said first roll means on its axis, second drive means for rotating said frame carrying said first and second roll means about an axis through said nip at substantially the same speed and in the same direction as that of said first roll means, and control means to actuate said second drive means in response to signals to rotate said frame carrying said roll means about an angle of 180* about an axis through said nip while said first drive means is continuously driving said first roll means such that there is no apparent movement of said roll means to effect the top of the sheets becoming the bottom and the trailing edge thereof becoming the leading edge.
 2. Apparatus according to claim 1 wherein said control means includes sheet sensing means for generating electrical signals.
 3. Apparatus according to claim 2 wherein said signals actuate electrical clutch means drivingly connected to said frame.
 4. Apparatus according to claim 3 wherein said electrical signals actuate a solenoid operated latch released momentarily out of the path of said frame. 